Emerged at my house on February 1, 2008, from galls collected in November 2007. The galls were on Quercus virginiana
, an oak not native to California and planted in a Manteca park. See this set
of gall/leaf images.
Identified using Weld (1)
and the help of Kathy Schick. Also, Kathy and some cynipid folks from Europe found more non-native Quercus virginiana
trees on the San Joaquin Delta College campus (same county as these, different town) with the same galls!